SBIR Phase II: MEMS Resonant Nanobalance Dew Point Meters

该小型企业创新研究(SBIR)二期项目旨在开发一种基于微电子机械系统(MEMS)的水分(露点)测量仪器。各种工业部门都需要微量水分测量，包括天然气生产和分销、半导体制造、纯天然气供应、航空航天和石化加工。商业化的湿度传感器要么非常昂贵，要么缺乏许多现有应用所需的准确性、长期稳定性和响应性。该方法的创新之处在于使用了微型机电谐振天平和冷却元件。该仪器将使用高精度的冷冻面技术测量露点，在谐振天平的表面沉积一层水分，从而将冷冻面测量技术的精确度与MEMS的小尺寸、低功耗和经济实惠相结合。MEMS谐振天平能够检测到低至几飞微克的沉积水分。因此，只需要在短时间内(即低功率/电池运行)冷却非常少量的气体，以沉积足够的水来指示露点。该测量技术的自调零能力消除了频繁维护和校准的需要。该项目的更广泛影响/商业潜力包括水分测量技术的重大飞跃，这些技术在过去几十年中没有经历过重大发展。拟议的新型露珠指针提供了更高的准确性、响应性、稳定性和稳健性，目前在相同的价格范围内是无法提供的。具有重大国家意义的一个重要的即期市场是天然气中水分的测量。在寒冷的气候中，天然气管道中过多的水可能会冻结管道关闭，使管道无法使用，直到冰点被识别和清除。此外，由于水分含量的多变性以及完全缺乏合适和负担得起的测量设备，天然气行业采用湿天然气作为定价标准，导致定价误差高达1.74%。拟议的电池或太阳能传感器将允许无人值守操作和数据传输能力，并将安装在天然气井口以及配电网络沿线这些类型的测量需求很高的不同点。

This Small Business Innovation Research (SBIR) Phase II project aims to develop a micro-electro-mechanical system (MEMS)-based moisture (dew point) measurement instrument. Trace moisture measurements are needed in a variety of industrial sectors including natural gas production and distribution, semiconductor manufacturing, pure gas supply, aerospace, and petrochemical processing. Commercially-available moisture sensors are either very expensive, or alternatively lack the required accuracy, long-term stability, and responsiveness for many existing applications. The innovative aspect of the proposed approach is the utilization of micro-electro-mechanical resonant balances coupled with a cooling element. The instrument will measure dew point using the highly accurate chilled surface technique to deposit a layer of moisture on the surface of the resonant balances, hence combining the accuracy of the chilled surface measurement technique the with small size, low power consumption and affordability enabled by MEMS. The MEMS resonant balances are capable of detecting as little as a few femto-grams of deposited moisture. Therefore, only a very small amount of gas needs to be chilled for a short period of time (i.e. low power/battery operation) to deposit sufficient water to indicate the dew point. The self-zeroing capability of the measurement technique eliminates the need for frequent maintenance and calibration.The broader impact/commercial potential of this project includes a significant leap forward in the moisture measurement technologies that have experienced no major development over the past several decades. The proposed new class of dew pointers offers higher accuracy, responsiveness, stability, and robustness currently unavailable at the same price range. An important immediate market with great national significance is the measurement of moisture in natural gas. In cold climates excess water in the gas pipeline can freeze the pipe shut, rendering the pipeline useless until the frozen point can be identified and cleared. Furthermore, due to the variability of the moisture content and the complete lack of suitable and affordable measurement equipment, wet gas is being used as the pricing standard in the natural gas industry, leading to pricing errors of up to 1.74%. The proposed battery- or solar-powered sensors will permit unattended operation and data transmission capability and will be installed at the natural gas wellheads as well as different points along the distribution network where these types of measurements are in high demand.